CVE-2026-42090

critical · 9.6

Notesnook is a note-taking app focused on user privacy & ease of use. Prior to Notesnook Web/Desktop version 3.3.15 and prior to Notesnook iOS/Android version 3.3.20, a stored XSS vulnerability in the note export flow can be escalated to remote code execution in the desktop app. The root cause is that exported note fields such as title, headline, and content are inserted into the generated HTML template without HTML escaping. When the note is later exported to PDF, Notesnook renders that HTML into a same-origin, unsandboxed iframe using iframe.srcdoc = .... Injected script executes in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with nodeIntegration: true and contextIsolation: false. This issue has been patched in Notesnook Web/Desktop version 3.3.15 and Notesnook iOS/Android version 3.3.20.

9.6

CVSS

0.5%

EPSS (exploit prob.)

40th

EPSS percentile

2026-05-04

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Weaknesses

CWE-79CWE-94

Affected products

Vendor	Product	Affected versions
streetwriters	notesnook_desktop	< 3.3.15
streetwriters	notesnook_mobile	< 3.3.20
streetwriters	notesnook_mobile	< 3.3.20

Check a specific version with /api/v1/cve/match.

References

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-42090